Rotary selector switch



March 11, 1952 BARRY 2,588,793

ROTARY SELECTOR SWITCH Filed July 28, 1950 2 SHEETS-SHEET l INVENTORATTORNEYS March 11, 1952 RY 2,588,793

ROTARY SELECTOR SWITCH Filed July 28, 1950 2 SHEETS-SHEET 2 IN VENTORATTORNEYJ Patented Mar. 11, 1952 ROTARY SELECTOR SWITCH Leon G. Barry,Whippany, N. J., assignor to United States Instrument Corporation,Summit, N. J., a corporation of New Jersey Application July 28, 1950,Serial No. 176,465

7 Claims 3 This invention relates to rotary selector switches, and moreparticularly to a switch which is very small in size yet is capable oftransferring a multiplicity of circuits between two or more positions.

The general object of the invention is the pro vision of a novel switchdeck assembly for in' corporation in a multiple deck rotary switch ofthe character described, which switch deck comprises a stator having aplurality of fixed contact members associated therewith, and a rotorhaving a plurality of bridging contacts mounted thereon, the respectivefixed and bridging contacts being secured and maintained in position bynovel, simple and inexpensive means which facilitate the speedy andinexpensive assembly of the device into an integrated unit or package,any desired number of such units being then assembled on a shaft,together with an indexing mechanism, to complete a switch assembly forthe control of the desired number of circuits.

A further object is the provision, in a switch deck unit of thecharacter described, of a stator of molded insulating material, forexample synthetic plastic material, having a plurality of upstandingprojections disposed in circular arrangement, together with an equalnumber of fixed contact members each comprising a tubular portionadapted to encircle one of said upstanding projections, and a straightportion projecting radially outwardly of the molded stator for theconnection ofa conductor thereto. Another object is the provision in aswitch deck unit of the character described of a rotor of moldedinsulating material, such as a synthetic plastic material,

provided with a plurality of upstanding projections disposed in circulararrangement, together with bridging contact members of conductive metalencircling each of said upstanding projections, together with resilientmeans for urging said contact members outwardly into engagement with thefixed contacts of the stator.

A further object is the provision, in a switch deck unit of thecharacter described in the preceding paragraphs, of a cover memberpermanently secured to the rotor after the bridging contacts are inplace and therefore serving to maintain them permanently in position,and a cover member permanently secured to the stator after the statorcontacts and rotor are assembled therewith, and serving to maintain thestator contacts and the rotor, which has already been permanently sealedas aforesaid, in position with regard to the stator, thus completing theaforesaid integrated unit.

Other and further objects, features and advantages will be apparent fromthe description which follows, read in connection with the accompanyingdrawings in which Figure 1 is a front elevation of a multi-deck switch,including operating knob, the several decks of which are constructed inaccordance with the invention;

Figure 2 is a side elevation of the switch of Fig- Figure 3 is a frontelevation of a switch deck unit with cover broken away;

Figure 4 is a sectional view on line 4-4 of Figure 3;

Figure 5 is a front elevation of a rotor according to the invention;

Figure 6 is a side Figure 5;

Figure 7 is a sectional view on line Figure 3;

Figure 8 is a sectional view on line Figure 3;

Figure 9 is a sectional view on line Figure 3;

Figure 10 is a perspective view of a bridging or rotor contact;

Figure 11 is a perspective view of a fixed or stator contact; and

Figure 12 is a perspective view of a bifurcated leaf spring for urgingthe bridgin contacts outwardly.

In order to facilitate an understanding of the invention, reference ismade to the embodiment thereof shown in the accompanying drawings anddetailed descriptive language is employed. It will nevertheless beunderstood that no limitation of the invention is thereby intended andthat various changes and alterations are contemplated such as wouldordinarily occur to one skilled in the art to which the inventionrelates.

Referring to Figures 1 and 2, a complete switch assembly employingswitch deck units according to the present invention comprises anydesired number of switch decks l0 mounted on shaft H on which are alsomounted an indexing mechanism I 2 and an operating knob l3. The indexingmechanism may be of any suitable type, but it is preferred to employ amechanism such as described and claimed in my ccpending applicationSerial No. 174,879, filed July 20, 1950, which was issued as Patent No.2,579,169 on December 18, 1951. The several switch decks and theindexing mechanism are secured together by means of bolts l4 and nutsI5, and the entire assembly may conveniently be mounted in a panel 16 byelevation of the rotor of means of threaded bushing I1, nut l8 andwasher l8, the panel being clamped between the latter and the hubportion H) of the indexing mechanism.

Referring now to Figures 3 and 4, the switch deck unit comprisesgenerally a stator 20 and rotor 2| which are preferably molded ofinsulating material such as a synthetic plastic material, for example,of molded nylon. The stator 29 is formed with a central circularaperture into which fits the hub portion 22 of the rotor 2|, the latterbeing telescoped into the stator 20 as seen in Figure 4. The rotor isformed with a central squared aperture 23 therethrough for reception ofa squared portion of the shaft The first switch deck l behind theindexing mechanism |2 is insulated therefrom by means of a phenolic orother separator plate 25.

The stator 20 is formed to provide a circular series of upstanding,preferably cylindrical projections 29 corresponding to the number offixed contact members which it is desired to employ in the switch deckunit and each projection 26 is provided with a contact member 21,preferably of resilient metal, formed to provide a tubular portion 28which encircles the cylindrical projection 26 and a straight portion 29which extends radially outwardly from the tubular portion. The straightportion 29, in the illustrated embodiment, comprises two prongsconsisting in the respective ends of the metal strip of which thecontact member consists, which ends lie parallel and adjacent eachother, the tubular portion 28 of the contact member being formed of thematerial in the central portion of said strip. Preferably, the straightportion 29 is perforated as at 39 (Figure 4) to facilitate the solderingof a conductor thereto.

The stator is also provided with upstanding projections 3| extendinginwardly from the periphery of the stator and terminating in a narrowpointed portion extending between adjacent fixed contacts and serving toincrease the length of the leakage or creepage path between adjacentcontacts. The straight portions 29 of the respective contacts extendoutwardly through slots between adjacent edges of adjacent projections3| and, due to the spring action of the resilient material of which theyare made, frictionally engage the respective edges of said slots.

The stator is also formed to provide four anguraly spaced projections orbosses 32 the radially inner portions of which correspond in shape tothe radially inner portions of the projections 3!, and the radiallyouter portions of which are provided with through apertures 33 toreceive the bolts I4. The bosses 32 are formed to provide short upwardlyextending sleeve portions 34 (Figure 8) for a purpose to be laterdescribed.

The rotor 2| as best seen in Figure 5, is circular in outline and isformed with a hub 35 which extends to substantially the same height asthe projections 3| and contact members 21 of the stator. Four arms 36extend radially outward from the hub 35 and provide therebetween thesubstantially semi-circular coves 31,

the respective arms 36 being notched on either side, as at 35', atpointsnear their outer ends, to receive the respective ends ofbifurcated leaf springs 39 (Figure 12).

Lying within each cove 3'! of the rotor is an upstanding generally ovalprojection 39 pro 'vided substantially centrally of its upper surfacewith a small cylindrical boss 40. The projec-- tions 39 carry thebridging contact sets 4|, each contact set comprising two rings 4|, 4|"(Figure 10) of conductive metal. The rotor contacts as well as thestator contacts are preferably provided with laminated silver coatingsto improve their conductivity, and to reduce wear and erosion. Each ofthe rings 4|, 4|" is separately urged radially outwardly by one of thebifurcations of the leaf spring 38, which is retained between theinnermost point of the bridging contact set 4| and the notches 36'formed in the respective sides of the arms 36.

After the bridging contacts 4| together with the leaf springs 33 areassembled on the rotor, a ring or cover 42 of phenolic material or otherinsulating material is assembled to the rotor by means of the bosses 49formed on the tops of projections 39, the bosses extending throughcorresponding apertures in the cover 42 and being headed over by anysuitable means,

secured together, and the rotor cannot become displaced from the stator,nor can any of the fixed or rigid contact members, or leaf springs 38,become dislodged. The cover 43 is preferably provided with punched,inwardly extending shallow bosses 44 (Figure 4) which project into theouter ends of the tubular portions 28 of the fixed contacts thuscooperating with the projections 26 in firmly anchoring the fixed orstator contact members. The switch deck thus becomes an integrated unitand may be manufactured, sold, transported and installed as such,without danger that any disarrangernent of the parts may take place.

From the foregoing description it will be apparent that the presentinvention provides a simple, inexpensive, easily assembled and foolproofswitch deck unit for rotary switches, as well as one that is especiallyefficient, due to the self-cleaning action of the rotary contacts 4|,and the firm yet yielding engagement between the bridging contacts andfixed contacts, secured by virtue of the leaf springs 38. The wholedevice may be made to occupy very little space, a switch deck such asthat illustrated in the drawings, and provided with twelve fixedcontacts, having an overall diameter of approximately one inch. Such aswitch, naturally, conserves a great deal of panel space ininstallations in which a multiplicity of switches are necessary.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

l. A rotary switch unit comprising a stator and a rotor, said statorbeing formed of molded plastic and being provided with a plurality ofupstanding projections arranged in a circle, and a contact memberassociated with each said projection and having a tubular portionencircling said projection and a straight portion projecting radiallyoutwardly of said stator, said rotor being concentric with and ofsmaller diameter than said stator, and being formed of molded plasticand generally circular in outline, and being provided with a pluralityof upstanding projections spaced about its periphery, a bridging contactmounted on each said rotor projection and having an outer dimension atleast equal to the distance between two adjacent stator contacts, springmeans urging said bridging contacts outwardly to engage said statorcontacts, means permanently secured to said rotor for holding saidbridging contacts in position, and cover means permanently secured tosaid stator for holding said stator contacts and said rotor in position,the whole constituting a permanently integrated unit.

2. The combination of claim 1, said stator being formed with a pluralityof peripherally disposed upstanding projections alternating with saidstator contact members and increasing the leakage path therebetween.

3. The combination of claim 2, said peripher: ally disposed projectionsbeing closely spaced to provide narrow slots therebetween, said straightportions of said stator contacts projecting outwardly through saidslots.

4. The combination of claim 3, each said stator contact having twosubstantially parallel straight portions projecting through said slotand being formed of resilient metal, said straight portions being urgedapart by spring action to engage the edges of said slot.

5. The combination of claim 1, said last means having a plurality ofcircularly arranged downwardly projecting bosses engaging within saidtubular portions of said stator contact members.

6. The combination of claim 1, each said bridging contact comprising twogenerally oval rings adapted to fit over one of said rotor projectionsin superposed relation.

7. The combination of claim 6, means comprising a bifurcated mountedbehind each said bridging contact, one of said bifurcations engagingeach of said rings and urging the same radially outwardly.

saidspring leaf spring LEON G. BARRY.

REFERENCES CITED UNITED STATES PATENTS me Date Number Na Smith Sept. 11,1945

